Engineers working to fix problems at Allen ISD’s $60 million Eagle Stadium believe the concourse where extensive concrete cracking was found won’t need to be demolished, based on preliminary information.

A final decision on how the district will address the web of cracks in the concourse is months away. But experts hired by Allen ISD are considering a waterproof overlay that would bridge gaps, according to an email obtained through an open records request by The Dallas Morning News.

Engineers have also discussed applying fiber-reinforced polymer, or FRP, to the underside of the concourse. In the construction industry, this fabric-like material is used to strengthen structures.

“All indications are right now … that no, we’re not looking at a tear-down,” Superintendent Lance Hindt said.

However, the horseshoe-shaped concourse is one of the last items in the repair list, and the district hasn’t gotten that far yet, Hindt said.

The first item on the list was the main scoreboard, which crews began repairing Aug. 5. The architectural firm that designed the stadium, PBK, issued a check to cover the $280,000 cost.

In a preliminary report issued January, Nelson Forensics — the firm hired by Allen ISD to study the problems at the stadium — described four potential remedies to the concourse cracking.

One solution combines epoxy injections to seal cracks and a pedestrian-traffic membrane that prevents moisture from seeping into the concrete. The overlay is liquid-applied and would resemble the concrete surface intended by the original design.

“This hybrid solution restores the structural capacity of the structure,” the report reads.

Or, as part of the same solution, FRP can replace epoxy injections for reinforcement, Nelson wrote.

FRP is commonly used for structure repairs, said Shih-Ho “Simon” Chao, an associate professor of engineering at the University of Texas at Arlington. The material is lightweight, but in tension, it can be stronger than steel.

“If you pull it, it’s very hard to break it,” Chao said.

When the capacity of concrete and reinforcing steel to support loads is compromised, FRP can be used to return capacity, Chao said. The material bonds with the structure when applied.

It’s unclear how much it might cost. Allen ISD is fixing the stadium in phases, so estimates will trickle in throughout the school year.

The traffic membrane solution is cheaper than tearing down the concourse, but it will require periodic inspection and reapplication of at least one coat, according to Nelson’s early report.

Allen ISD officials closed the 2-year-old stadium in February after Nelson found structural problems in the venue. Officials said they hope to reopen the stadium by May.

For months, PBK and general contractor Pogue Construction have promised that taxpayers won’t foot the bill to fix the facility. Nelson concluded engineering failures are mostly to blame for significant structural issues.

A July 28 email with a tentative design schedule shows August is the expected completion date for construction documents related to the basement/retaining walls and the lateral-load system in one-story buildings.

The email from Nelson offers a glimpse into the design process for the repairs, which will take place in six phases. These may include two or more segments.

Nelson and Datum Engineers, another firm hired by Allen ISD to develop the repairs, are conducting meetings to discuss design concepts for a phase or segments. PBK and Pogue are involved in the meetings, Hindt said.

“It helps PBK and Pogue [engineers] to say, ‘Yeah, actually this does need to be done,’” Hindt said. “So they go back to the owners and say, ‘Look, they are not doing a betterment. This is the fix that is required based upon what we looked at.’”

For each phase, an engineering review will follow, and Datum accepts comments on the design documents. The district will use the documents to get early cost estimates.

About three weeks later, Datum is expected to issue signed and sealed construction documents. That’s when final bids will be secured, according to Allen ISD.

The preliminary schedule shows that engineers plan to release signed construction documents for several areas in October. These include the press box repairs, concrete columns, transfer girders, expansion joints, the gravity-load system in one-story buildings and part of the concourse.

More concourse documents should follow in November and January. Design related to the reinforcement of concrete-block walls might be ready in December.

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